Note: [default] means the software will assume (by default) you mean to search for a phrase when you string words together.

Note: n means "substitute any number\". Some systems may have an upper limit such as 10 or 25. In most cases, when you're searching for keywords in proximity to each other, you'll be using a small number. E.g., when you want to search either "water pollution\" or "pollution of the water\", you may search some form of "water within 3 words of pollution\".